A generic installation switching device can be, for example, a circuit breaker, a fault-current circuit breaker, a motor protection switch or the like. It comprises within its housing at least one contact point comprising at least one fixed and one moving contact member via which a current path leading from an input terminal to an output terminal can be opened and closed. The contact point is generally actuated by a switching mechanism with latching point. A generic installation switching device can also comprise tripping devices, for example a thermal trip or an instantaneous tripping magnet which, when a short circuit or fault current occurs in the current path, act on the contact point or the switching mechanism, respectively, so that the contact point is opened.
Apart from screw terminals, screwless clamping connections are also used for the connection to external connecting conductors in generic installation switching devices. In this context, plug-in terminals or spring-pull terminals can be used as clamping elements. In principle, these can considerably simplify the connection of connecting conductors but known installation switching devices with screwless terminal connections are still subject to considerable restrictions in use today.
From EP 1 432 077, a generic installation switching device with a screwless terminal connection is known in which the terminal connection space is open towards the narrow side of the housing and is covered with a cover part corresponding to the housing width in its width. The cover part is clipped to the housing on its narrow side. At the terminal connection according to EP 1 432 077, rigid conductors can be inserted without tools but the insertion of flexible conductors and the removal of the conductors from the terminal connection require the use of a tool.
From EP 1 089 379, a generic installation switching device comprising a clamping spring housing moulded separately onto the housing is known in which the conductors can be inserted and extracted without use of a tool. Due to the clamping spring housing being moulded on separately, the construction is very elaborate however and is additionally restricted to the use of spring-pull terminals.
EP 1 124 286 shows a generic installation switching device with plug-in terminals which, however, are accommodated on a separate terminal block, wherein the terminal block must be subsequently plugged onto the switching device. In this respect, the solution demonstrated here is very elaborate and requires additional parts for plugging on to the installation switching device so that no standardized uniform housings can be used.